text: Ionochromism is the process of reacting an ionochromic material with a charged species, or a positively or negatively charged ion. Materials that have ionochromic properties exhibit reversible color change, where the absence of a stimulus such as an ionic species can result in the compound changing to its original color.
  Various ionic color changing mechanisms that are used in chromic processes can be used in ionochromism, including: 
  # Halochromism 
  # Acidochromism 
  # Metallochromism